why do people compare this game's artstyle to garfield they're literally nothing alike

It doesn't help that this game only came out in countries where baseball is a major sport and even then I'm not sure if all of the main playing countries got it (did South Korea get this game?). Probably if it wasn't for that video and seeing the characters, then it most likely would have been just as ignored in the Americas due to declining interest in baseball and how the game is set up, not every Nintendo published game gets remembered. Also do think that Nintendo of America was lucky to localize the game, if it was done in the past or even now it would have stayed in Japan...

Europe got Nintendo Pocket Football Club instead, part of the Calcio-bit series and is a football manager type of game (but with players that look like sprites and not as "spreadsheet" focused). No Garfield mixed with a walrus looking dog here...

For the record I bought and completed this game (nearly, I don't think I ever got top ranks on the toughest minigames) when it came out, it just didn't grab most people's attention because a collection of baseball minigames with built-in microtransactions is a weirdly specific thing. But the minigames are really fun!

So a youtube video is what got people interested in this game?

Thing is these 2-dimensional storyboard illustrations actually look pretty good. The game would be a lot more visually-appealing if they'd just gone with that sort of style throughout.
Also Pappy still looks to be in the same style as the Japanese "Sports Store" design.

@Doc von Schmeltwick Yikes! The buck teeth make it worse.

Likely had to do with how over-the-top Japanese he looked.

Rusty's Japanese design is totally different though, it makes wonder why they changed it... But the original design appeared in Smash as a Spirit along with the West version.

What is it anyways? I saw the weird bad CG Garfield-looking thing on the eShop ages ago and had no idea what it was.

This game's art style looks almost identical to that of Garfield's.

It really says something about this game when the sprites took a Youtube video to get anyone's interest on ripping the sprites

yes